586 research outputs found
On the Credibility of the Irish Pound in the EMS
This paper assesses the degree of credibility of the Irish Pound in the European Monetary System between 1983 and 1997. Different credibility indicators proposed in the literature are used to measure agents’ perceptions of the credibility of the ERM commitment in an attempt to distinguish between events stemming from problems in the ERM itself and those that appear to have been exclusive to Ireland.
The spectral type of CHS7797 - an intriguing very low mass periodic variable in the Orion Nebula Cluster
We present the spectroscopic characterization of the unusual high-amplitude
very low mass pre-main-sequence periodic variable CHS7797. This study is based
on optical medium-resolution (R=2200) spectroscopy in the 6450-8600 A range,
carried out with GMOS-GEMINI-S in March 2011. Observations of CHS7797 have been
carried out at two distinct phases of the 17.8d period, namely at maximum and
four days before maximum. Four different spectral indices were used for the
spectral classification at these two phases, all of them well-suited for
spectral classification of young and obscured late M dwarfs. In addition, the
gravity-sensitive NaI (8183/8195 A) and KI (7665/7699 A) doublet lines were
used to confirm the young age of CHS7797. From the spectrum obtained at maximum
light we derived a spectral type (SpT) of M6.05, while for the spectrum taken
four days before maximum the derived SpT is M5.75. The derived SpTs confirm
that CHS7797 has a mass in the stellar-substellar boundary mass range. In
addition, the small differences in the derived SpTs at the two observed phases
may provide indirect hints that CHS7797 is a binary system of similar mass
components surrounded by a tilted circumbinary disk, a system similar to KH15D.Comment: 6 pages, accepted for publication A&
Molecular and phenotypic comparisons of salt effects on soybean cultivars with differential chloride uptake capacities
Genetic manipulation of crop plants, through breeding or transgenic approaches, for enhanced tolerance to abiotic stress holds great promise for improving yields and promoting new methods for sustainable agriculture. This study examines the potential role that genes of the soybean, Glycine max L., encoding elongation factor-1 alpha (EF-1α) and glyoxalase I (GlxI) might play in response to salt stress. Previous reports have suggested a possible function for both GlxI and EF-1α in conferring enhanced salt tolerance in other plant species. In addition to other possible mechanisms, salt tolerance in soybeans can be regulated by plant uptake and transport of chloride ions. Soybean lines that transfer chloride to their foliage from the soil are termed “includers” and are considered to be more susceptible to salt stress than their counterparts, “excluders” that do not transport chloride into their leaves. We used chloride “includers”, cv. Clark and Dare, and “excluders”, cv. Lee68 and S100, to compare gene expression responses and plant susceptibility to chloride salts. Mineral analysis of Clark and Lee68 cultivars by inductively coupled plasma mass spectrometry was performed to verify the differences in chloride uptake. In an optimized greenhouse screening procedure, the excluder cv. Lee68 demonstrated fewer visual symptoms of salt stress when treated with the same salt concentrations as the includer, cv. Clark. RNA blots showed the soybean genes encoding EF-1α and I GlxI were equally induced in both includers and excluders following treatment with NaCl or CaCl2 . Although transcript levels for EF-1α and GlxI are induced by salt treatments, transcript profiles do not differ between salt-tolerant and susceptible soybean cultivars. This suggests that the cultivars respond to salt stress in similar ways, but that these genes are not responsible for the differential phenotypes
Catalytic reforming of dimethyl ether in microchannels
© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The steam reforming and oxidative steam reforming of dimethyl ether (DME) were tested at 573–773¿K over a CuZn/ZrO2 catalyst in microreactors with three different types of channels: ceramic square channels with side lengths of 900 and 400¿µm, and silicon microchannels of 2¿µm of diameter. The channels were first coated with ZrOCl2 (ceramic channels) or Zr(i-PrO)4 (silicon microchannels) and calcined at 773¿K for 2¿h to obtain a homogeneous and well-adhered ZrO2 layer, as determined by SEM, and then Cu and Zn (Cu:Zn¿=¿1:1¿M, 20¿wt% total metal) were co-impregnated. Operation at highly reduced residence time (10-3¿s) while achieving hydrogen yields similar to those recorded over the ceramic channels was possible for the silicon microchannels due to the three orders of magnitude increased contact area. In addition, the amount of catalyst used for coating the silicon microchannels was two orders of magnitude lower with respect to the conventional ceramic channels. Outstanding specific hydrogen production rates of 0.9 LN of H2 per min and cm3 of reactor volume were achieved as well as stable operation for 80¿h, which demonstrates the feasibility of using on-site, on-demand hydrogen generation from DME for portable fuel cell applications.Peer ReviewedPostprint (published version
La esclerosis lateral amiotrófica (ELA) desde la Atención Primaria. Epidemiología y características clínico-asistenciales
La ELA es una enfermedad poco frecuente en atención primaria (AP), representa un desafío para el médico de familia especialmente en atención domiciliaria. Objetivo Conocer la incidencia y prevalencia de la ELA en un área de gestión de AP, las características clínicas y la utilización de recursos sanitarios. Diseño Estudio observacional. Emplazamiento Dirección de AP Costa de Ponent, Región Sanitaria Metropolitana Sur, Barcelona, Cataluña, España. Participantes Pacientes con ELA ≥18 años diagnosticados hasta el 01/03/2017. Mediciones principales Edad, sexo, características: forma de inicio (espinal, bulbar, otras), intervalo entre inicio de síntomas y diagnóstico, portadores gastrostomía percutánea, ventilación no invasiva o invasiva. Identificación en AP como paciente crónico complejo o con necesidades paliativas. Inclusión en programas de atención domiciliaria (PAD). Modelo de atención hospitalario. Resultados Ochenta y un pacientes, edad media 65,6 años (±11,7), varones 49,4%. Forma de inicio: espinal 69%, bulbar 21%, otras 4%. Intervalo entre inicio de síntomas y diagnóstico 12 meses. Identificados como paciente crónico complejo o con necesidades paliativas 13,6%, incluidos en PAD 29 pacientes (35,8%). Atendidos en modelo hospitalario integral 79 pacientes (97,5%). Prevalencia 6,1/100.000 habitantes en 2017. Incidencia anual entre 1,2 casos/100.000 habitantes/año en 2012 y 3,5 casos/100.000 habitantes/año en 2016. Conclusiones Utilizar gastrostomía percutánea en la ELA favorece la identificación como paciente crónico complejo o con necesidades paliativas e inclusión en PAD. Utilizar ventilación no invasiva favorece la inclusión en PAD. Los datos de incidencia y prevalencia de ELA son superiores a los descritos previamente en la misma área. Es necesaria la identificación precoz de estos pacientes en los modelos de atención a la cronicidad en equipos de AP
Voltage dip generator for testing wind turbines connected to electrical networks
This paper describes a new voltage dip generator that allows the shape of the time profile of the voltage generated to be configured. The use of this device as a tool to test the fault ride-through capability of wind turbines connected to the electricity grid can provide some remarkable benefits: First, this system offers the possibility of adapting the main features of the time–voltage profile generated (dip depth, dip duration, the ramp slope during the recovery process after clearing fault, etc.) to the specific requirements set forth by the grid operation codes, in accordance with different network electrical systems standards. Second, another remarkable ability of this system is to provide sinusoidal voltage and current wave forms during the overall testing process without the presence of harmonic components. This is made possible by the absence of electronic converters. Finally, the paper includes results and a discussion on the experimental data obtained with the use of a reduced size laboratory prototype that was constructed to validate the operating features of this new device
Evaluating the feasibility of using Sentinel-2 imagery for water clarity assessment in a reservoir
The new Sentinel-2 satellites present a significant scientific opportunity for the study of water quality. The objective of this study was to evaluate the suitability of Sentinel-2 imagery for estimating and mapping Secchi disk transparency (SDT) in Río Tercero reservoir (Córdoba-Argentina). Field observations and a dataset of atmospherically corrected Sentinel-2 images were used to generate and validate an algorithm to estimate water clarity in the studied reservoir. As a real application of the used methodology, the validated algorithm was used to obtain a spatial representation of water clarity in the reservoir during sampling campaigns. Results demonstrate capabilities of Sentinel-2 mission to make a substantial contribution to the current assessment and understanding of aquatic systems by estimating and mapping a water quality characteristic.Fil: Bonansea, Matias. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Ciencias de la Tierra, Biodiversidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencias de la Tierra, Biodiversidad y Ambiente; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Estudios Básicos y Agropecuarios; ArgentinaFil: Ledesma, Micaela. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Estudios Básicos y Agropecuarios; ArgentinaFil: Bazán, Raquel. Universidad Nacional de Córdoba; ArgentinaFil: Ferral, Anabella. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: German, Alba. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Ministerio de Agua, Ambiente y Servicios Públicos. - Gobierno de la Provincia de Cordoba. Ministerio de Agua, Ambiente y Servicios Publicos.; ArgentinaFil: O Mill, Patricia. Universidad Nacional de Córdoba; Argentina. Ministerio de Agua, Ambiente y Servicios Públicos. - Gobierno de la Provincia de Cordoba. Ministerio de Agua, Ambiente y Servicios Publicos.; ArgentinaFil: Rodriguez, Claudia. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Estudios Básicos y Agropecuarios; ArgentinaFil: Pinotti, Lucio Pedro. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Ciencias de la Tierra, Biodiversidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencias de la Tierra, Biodiversidad y Ambiente; Argentina. Universidad Nacional de Córdoba; Argentin
Cátedra Xavier Moyssén Echeverría: México: angustia de sus cristos
El presente libro compila los trabajos presentados durante la segunda edición de la “Cátedra Extraordinaria Xavier Moyssén Echeverría” de la Universidad Autónoma del Estado de México (2014). En dicho evento se procuró centrar la reflexión académica en una de las obras más representativas de este historiador del arte mexicano: México: angustia de sus cristos, libro publicado por el Instituto Nacional de Antropología e Historia en 1967
Membrane shape as a reporter for applied forces
Recent advances have enabled 3-dimensional reconstructions of biological structures in vivo, ranging in size and complexity from single proteins to multicellular structures. In particular, tomography and confocal microscopy have been exploited to capture detailed 3-dimensional conformations of membranes in cellular processes ranging from viral budding and organelle maintenance to phagocytosis. Despite the wealth of membrane structures available, there is as yet no generic, quantitative method for their interpretation. We propose that by modeling these observed biomembrane shapes as fluid lipid bilayers in mechanical equilibrium, the externally applied forces as well as the pressure, tension, and spontaneous curvature can be computed directly from the shape alone. To illustrate the potential power of this technique, we apply an axial force with optical tweezers to vesicles and explicitly demonstrate that the applied force is equal to the force computed from the membrane conformation
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